奥氏体化温度及冷却方式对20Mn2SiVB钢组织及性能的影响

通过各种试验手段,研究了20Mn2SiVB钢不同奥氏体化温度及不同冷却方式处理后其显微组织及其强度和塑性的变化,确定了最佳的热处理工艺。结果表明:900℃奥氏体化后风冷时钢的强塑性最好;在强塑性最佳时的微观组织是铁素体+粒状贝氏体。     

20CrMnTi钢粮机压辊碳氮共渗的应用研究

对粮机压辊在材料与热处理工艺方面进行了改进，并采用金相显微镜、硬度计、电子天平等设备对共渗层进行了组织、硬度、耐腐蚀性分析。与38CrMoAl钢氮化处理相比，20CrMnTi钢碳氮共渗处理得到了硬度与层深的适当配合．取得了模具成本降低50％、经济效益提高70％的良好效果。     

20G高压锅炉管裂纹原因分析

对20G高压锅炉管产生裂纹的原因进行了分析，结果表明是冷拔工艺不当所致。     

巧用CL-02DS中文设定显示单元

本文介绍了利用CL－02DS中文设定显示单元，配合程序设计，使之实现记录功能。     

Effect of temperature on vacuum hot bulge forming of BT20 titanium alloy cylindrical workpiece

Temperature is one of the key parameters for BT20 titanium alloy cylindrical workpiece manufactured by vacuum hot bulge forming. A two-dimensional nonlinear thermo-mechanical coupled FE model was established. Numerical simulation of vacuum hot bulge forming process of titanium alloy cylindrical workpiece was carried out using FE analysis software MSC Marc. The effects of temperature on vacuum hot bulge forming of BT20 titanium alloy cylindrical workpiece were analyzed by numerical simulation. The simulated results show that the Y-direction displacement and the equivalent plastic strain of the workpiece increase with increasing bulge temperature. The residual stress decreases with increasing bulge temperature. The optimal temperature range of BT20 titanium alloy during vacuum hot bulge forming is 750-850 ℃. The corresponding experiments were carried out. The simulated results agreed well with the experimental results.     

Sulfidation behavior of Fe-25Cr-20Ni-1.5Al2O3 in simulated coal combustion/gasification environments

The effect of minor addition of -Al₂O₃ dispersoids on the sulfidation behavior of Fe-25Cr-20Ni was investigated over a range of pO₂, 1.13×10^–20 to 1.18×10 ****^–22 atm. at constant pS₂=1.22×10^–8 atm. Fe-25Cr-20Ni and Fe-25Cr-20Ni 1.5 Al₂O₃ with and without preformed oxide scales were exposed to bioxidant gas mixtures H₂/H₂O/H₂S/Ar at 700° C. Both isothermal and cyclic exposures were included. Scales were characterized by a combination of several surface analytical tools. A remarkable improvement in sulfidation resistance is observed in Fe-25Cr-20Ni-1.5Al₂O₃ under the conditions investigated here. This is attributed to the ability of the alloy to form and maintain a predominantly Cr₂O₃ scale with reduced Fe-diffusion and content. Possible scientific reasons for such improvement are discussed. The base alloy, Fe-25Cr-20Ni, fails to develop and retain such a Cr₂O₃ scale and undergoes sulfidation within a few minutes of exposure. The scale breakdown process by sulfidation is explained qualitatively. Experimental evidence suggests that sulfur in the environment enhances Fe-diffusion and content in the scale.     

不同钢种对全浮动芯棒钢管热连轧过程影响的模拟分析

针对不同钢种的Ф152.5mm×5.75mm规格无缝钢管8机架连轧过程进行了测试,并应用三维有限元模拟仿真技术进行了有限元建模与仿真分析。通过与实测结果对比,建立的有限元模型及其边界条件合理可靠。模拟结果表明,连轧管内壁要承受较大作用力和塑性变形,需对芯棒表面进行较好润滑;连轧管机组减壁主要发生在1~4机架上,约占总减壁量的60%以上;20钢各道次外直径和壁厚变化好于T91钢;随道次增加,钢管拉应力增大,是导致钢管内表面出现拉凹的重要原因。     

20#钢在聚丙烯酰胺驱油溶液中的腐蚀行为

采用电化学测试和SEM、XRD、XPS等多种表面分析技术，对20#钢在聚丙烯酰胺驱油溶液中的腐蚀进行了系统的研究.结果表明：20#钢在聚丙烯酰胺驱油溶液中的腐蚀为活性溶解腐蚀；浸泡后20#钢表面产生了大量的腐蚀坑和腐蚀沟，形成的腐蚀产物为FeOOH，Fe3O4和Fe2O3；腐蚀产物晶粒细化，结构趋于非晶态；20#钢的腐蚀还会引起聚丙烯酰胺的降解，降低了聚丙烯酰胺驱油溶液的稳定性.      

1Cr20Co6Ni2WMoV钢热变形行为研究

文章采用Gleeble-2000热模拟试验机对1Cr20Co6Ni2WMoV热强钢的热变形行为进行研究。变形温度为950℃,1000℃,1050℃,1100℃,1160℃,变形速率为0．01s~(-1),0．1s~(-1),1s~(-1),10s~(-1)。结果表明．1Cr20Co6Ni2WMoV钢在低应变速率热压缩变形过程中发生明显的动态再结晶;当应变速率大于10s~(-1)时,只发生动态回复。动态再结晶晶粒随变形温度降低,应变速率升高而减小。随应变速率的提高,峰值应力和峰值应变均升高。